Chart B-1: Displays Blank
You have been directed to this chart from CHART B: DISPLAYS BLANK due to one or all displays are blank and the brake lamps do not work. This chart will determine why the BCM and CPS are not "Awake" and not able to function.
NOTE:
The following step numbers refer to circled numbers on diagnostic chart. See Fig 1
. For circuit identification, see Figure
.
- It has been determined that the BCM has the correct conditioned 12 volt input. This checks for proper 7 volt inputs.
- With the key on, in the run position there should be no "crank" input to the BCM. If the crank input remains HI the BCM and other components will not wake up, resulting in blank displays.
- With the key in the run position, the BCM should "Wake-Up" the CPS with a greater than 10 volt signal to the CPS on circuit 555. If this voltage is there, the problem must be a poor connection at the CPS. If there is no voltage, then the wire or BCM are suspect.